Packages with Passive Devices and Methods of Forming the Same
A device includes a substrate, a metal pad over the substrate, and a passivation layer having a portion over the metal pad. A Post-Passivation Interconnect (PPI) line is disposed over the passivation layer and electrically coupled to the metal pad. An Under-Bump Metallurgy (UBM) is disposed over and electrically coupled to the PPI line. A passive device includes a portion at a same level as the UBM. The portion of the passive device is formed of a same material as the UBM.
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This application is a divisional of U.S. patent application Ser. No. 13/464,081, entitled “Packages with Passive Devices and Methods of Forming the Same,” filed on May 4, 2012, which application claims the benefit of the following provisionally filed U.S. Patent Application: application Ser. No. 61/581,279, filed Dec. 29, 2011, and entitled “FO-WLP Extra Cu-PPI Process and System Electrical Shielding Solution;” which applications are hereby incorporated herein by reference.
BACKGROUNDWith the evolving of semiconductor technologies, semiconductor dies are becoming increasingly smaller. In the meantime, more functions need to be integrated into the semiconductor dies. Accordingly, the semiconductor dies need to have increasingly greater numbers of I/O pads packed into smaller areas, and the density of the I/O pads rises quickly with time. As a result, the packaging of the semiconductor dies becomes more difficult, which adversely affects the yield of the packaging.
Conventional package technologies can be divided into two categories. In the first category, dies on a wafer are packaged before they are sawed. This packaging technology has some advantageous features, such as a high throughput and a low cost. Further, less underfill or molding compound is needed. This packaging technology, however, also suffers from drawbacks. As aforementioned, the sizes of the dies are becoming increasingly smaller, and the respective packages can only be fan-in type packages, in which the I/O pads of each die are limited to a region directly over the surface of the respective die. With the limited areas of the dies, the number of the I/O pads is limited due to the limitation of the pitch of the I/O pads. If the pitch of the pads is to be decreased, solder bridges may occur. Additionally, under the fixed ball-size requirement, solder balls must have a certain size, which in turn limits the number of solder balls that can be packed on the surface of a die.
In the other category of packaging, dies are sawed from wafers before they are packaged, and only “known-good-dies” are packaged. An advantageous feature of this packaging technology is the possibility of forming fan-out packages, which means that the I/O pads on a die can be redistributed to a greater area than the die, and hence the number of I/O pads packed on the surfaces of the dies can be increased.
For a more complete understanding of the embodiments, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
The making and using of the embodiments of the disclosure are discussed in detail below. It should be appreciated, however, that the embodiments provide many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are illustrative, and do not limit the scope of the disclosure.
A package structure including Integrated Passive Devices (IPD) and the methods of forming the same are provided in accordance with an embodiment. The intermediate stages of manufacturing the package are illustrated. Variations of the embodiments are also discussed. Throughout the various views and illustrative embodiments, like reference numbers are used to designate like elements.
Referring to
Metal pillar 28 is formed in passivation layer 24, and is electrically coupled to bond pad 22. In some embodiments, metal pillar 28 has a bottom surface contacting the top surface of bond pad 22. Metal pillar 28 may comprise copper, and hence is alternatively referred to as copper pillar 28 throughout the description. However, other conductive materials such as nickel and/or aluminum may also be used to form copper pillar 28. In some embodiments, top surface 28A of copper pillar 28 is substantially level with top surface 26A of passivation layer 26. In other embodiments, top surface 28A of copper pillar 28 is lower than top surface 26A, and hence copper pillar 28 is in passivation layer 26, with a thin portion of passivation layer 26 covering copper pillar 28.
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The initial steps of these embodiments are essentially the same as shown in
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By using the UBM RDL to form the IPDs, the package areas are used better. The performance of the IPDs is improved. The formation of the IPDs does not require additional masks and lithography steps.
In accordance with embodiments, a device includes a substrate, a metal pad over the substrate, and a passivation layer having a portion over the metal pad. A Post-Passivation Interconnect (PPI) line is disposed over the passivation layer and electrically coupled to the metal pad. An Under-Bump Metallurgy (UBM) is disposed over and electrically coupled to the PPI line. A passive device includes a portion at a same level as the UBM. The portion of the passive device is formed of a same material as the UBM.
In accordance with other embodiments, a device includes a die, which includes a semiconductor substrate, a metal pad over the semiconductor substrate, a passivation layer including a portion over the metal pad, and a metal pillar over the metal pad and extending into the passivation layer. A molding compound encircles the die. A first dielectric layer is over the metal pillar, the passivation layer, and the molding compound. A PPI line is over the first dielectric layer and electrically coupled to the metal pad through the metal pillar and a via in the first dielectric layer. A second dielectric layer has a portion over the PPI line. A UBM is over and electrically coupled to the PPI line, wherein the UBM extends into the second dielectric layer. A solder region is over and connected to the UBM. A passive device includes a first portion in the first dielectric layer, and a second portion over the second dielectric layer.
In accordance with yet other embodiments, a method includes attaching a die over a carrier. The die includes a semiconductor substrate, a metal pad over the semiconductor substrate, a passivation layer having a portion over the metal pad, and a metal pillar over the metal pad and extending into the passivation layer. The die is molded with a polymer, with the polymer encircling the die. The method further includes forming a first dielectric layer over the metal pillar, the passivation layer, and the polymer, and forming first openings in the first dielectric layer. The metal pillar is exposed through one of the first openings. A PPI line is formed over the passivation layer and electrically coupled to the metal pad through the metal pillar and a via in the one of the first openings. A second dielectric layer is formed, and includes a portion over the PPI line. A UBM is formed to be over and electrically coupled to the PPI line. A solder region is formed over and connected to the UBM. At the time the UBM is formed, a portion of a passive device is formed simultaneously.
Although the embodiments and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the embodiments as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, and composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the disclosure. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. In addition, each claim constitutes a separate embodiment, and the combination of various claims and embodiments are within the scope of the disclosure.
Claims
1. A method comprising:
- molding a die in a polymer, with the polymer encircling the die;
- planarizing the polymer to expose a metal pillar of the die;
- forming an Under-Bump Metallurgy (UBM) electrically coupled to the metal pillar;
- forming a first portion of a passive device, wherein the first portion of the passive device and the UBM are formed simultaneously; and
- forming a solder ball on the UBM.
2. The method of claim 1 further comprising:
- before the forming the UBM, forming a Post-Passivation Interconnect (PPI) line, with the UBM electrically coupled to the metal pillar through the PPI line; and
- forming a second portion of the passive device, wherein the second portion of the passive device and the PPI line are formed simultaneously.
3. The method of claim 1 further comprising:
- after the planarizing the polymer, forming a dielectric layer overlying and contacting the polymer and the die;
- forming a via in the dielectric layer; and
- forming a third portion of the passive device, wherein the third portion of the passive device and the via are formed simultaneously.
4. The method of claim 1, wherein the first portion of the passive device comprises a portion overlapping the polymer.
5. The method of claim 1 further comprising:
- forming a dielectric mask layer over the passive device and the UBM; and
- patterning the dielectric mask layer to expose the solder ball, wherein the passive device is covered by a remaining portion of the dielectric mask layer.
6. The method of claim 1 further comprising:
- bonding the solder ball to a package component; and
- dispensing an underfill into a gap between the die and the package component, wherein the underfill contacts the passive device.
7. The method of claim 1, wherein the planarizing the polymer comprises performing a grinding step to level top surfaces of the metal pillar and the polymer.
8. The method of claim 1, wherein the passive device comprises a top surface level with a top surface of the UBM, and a bottom surface level with a top surface of the metal pillar.
9. A method comprising:
- attaching a die over a carrier, wherein the die comprises: a semiconductor substrate; a metal pad over the semiconductor substrate; a passivation layer comprising a portion over the metal pad; and a metal pillar over the metal pad and extending into the passivation layer;
- molding the die in a polymer, with the polymer encircling the die;
- forming a first dielectric layer over the metal pillar, the passivation layer, and the polymer;
- forming first openings in the first dielectric layer, wherein the metal pillar is exposed through one of the first openings;
- forming a Post-Passivation Interconnect (PPI) line, wherein the PPI line is electrically coupled to the metal pad through the metal pillar and a via in the one of the first openings;
- forming a second dielectric layer comprising a portion over the PPI line;
- forming an Under-Bump Metallurgy (UBM) over and electrically coupled to the PPI line;
- forming a solder region over and connected to the UBM; and
- forming a first portion of a passive device, wherein the first portion of a passive device and the UBM are formed simultaneously.
10. The method of claim 9, wherein the first openings comprise portions over and aligned to the polymer, and wherein at a time the PPI line is formed, a metallic material is filled into portions of the first openings to form a second portion of the passive device.
11. The method of claim 9 further comprising patterning the second dielectric layer to form second openings, wherein the second openings are filled to form an additional portion of the passive device.
12. The method of claim 9 further comprising:
- forming a dielectric mask layer over the passive device and the UBM; and
- patterning the dielectric mask layer to expose the solder region, wherein the passive device is covered by a remaining portion of the dielectric mask layer.
13. The method of claim 9 further comprising:
- bonding the solder region to a package component; and
- dispensing an underfill into a gap between the second dielectric layer and the package component, wherein the underfill contacts the passive device.
14. The method of claim 9 further comprising, before the step of forming the first dielectric layer, performing a grinding step to level a top surface of the metal pillar, the passivation layer, and the polymer.
15. The method of claim 9, wherein the first portion of the passive device comprises a portion overlapping the polymer.
16. The method of claim 9, wherein the passive device comprises a top surface level with a top surface of the UBM, and a bottom surface level with a top surface of the metal pillar.
17. A method comprising:
- molding a die with a polymer, with the polymer encircling the die;
- planarizing the polymer to expose a metal pillar of the die;
- forming an Under-Bump Metallurgy (UBM) electrically coupled to the metal pillar;
- forming a first portion of a passive device, wherein a first portion of the passive device and the UBM are formed simultaneously in a same process step, and wherein the first portion of the passive device comprises a portion overlapping the polymer; and
- forming a solder ball over and in physical contact with the UBM.
18. The method of claim 17 further comprising:
- before the forming the UBM, forming a Post-Passivation Interconnect (PPI) line, with the UBM electrically coupled to the metal pillar through the PPI line; and
- forming a second portion of the passive device, wherein the second portion of the passive device and the PPI line are formed simultaneously in a same additional process step.
19. The method of claim 17 further comprising:
- after the planarizing the polymer and before forming the UBM, forming a dielectric layer overlying and contacting the polymer and the die;
- forming a via in the dielectric layer, with the UBM electrically coupled to the metal pillar through the via; and
- forming a third portion of the passive device, wherein the third portion of the passive device and the via are formed simultaneously in a same additional process step.
20. The method of claim 17, wherein the passive device comprises a top surface level with a top surface of the UBM, and a bottom surface level with a top surface of the metal pillar.
Type: Application
Filed: Nov 14, 2013
Publication Date: Mar 13, 2014
Patent Grant number: 9040381
Applicant: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD. (Hsin-Chu)
Inventors: Chen-Hua Yu (Hsin-Chu), Shang-Yun Hou (Jubei City), Der-Chyang Yeh (Hsin-Chu), Shuo-Mao Chen (New Taipei City), Chiung-Han Yeh (Tainan), Yi-Jou Lin (Hsin-Chu)
Application Number: 14/080,014
International Classification: H01L 21/56 (20060101);